German Patent DE 44 03 402 A1 discloses a heat exchanger that features two coolant boxes with a tube block including several parallel tubes that may have a flat configuration. An inlet tube may be attached to one coolant box at one front side via a connector pipe. Accordingly, outlet tubes are attached to the other coolant box by means of suitable connecting pipes. Connecting individual tubes to the associated coolant boxes is particularly expensive.
German Patent DE 197 19 255 A1 describes another heat exchanger, in which one of the coolant boxes contains three chambers, namely an inlet chamber, a reversal chamber and an outlet chamber. Inlet tubes are attached to the fronts of these coolant boxes, and the inlet tube is connected to the inlet chamber, while the outlet tube is connected to the outlet chamber. Such a frontal connection of the tubes to the boxes is relatively complicated.
German Patent DE 35 11 952 C2 describes a heat exchanger with a coolant box made of plastic. This special coolant box contains two inlet chambers, one outlet chamber, and corresponding connector pipes that are integrated into the coolant boxes for attachment of the inlet tubes and of the outlet tube. The outlet chamber of this coolant box has an additional peculiarity, since it is divided into an inlet region and an outlet region, and these regions are connected to each other by means of an overflow opening. The coolant flows from the tube block into the inlet region of the outlet chamber and moves from there through the overflow opening into the outlet region of the outlet chamber. From the outlet chamber the coolant then flows into the outlet tube. Due to the cross sectional design of the overflow opening, a specific flow and thus a specific heat distribution in the tube block can be established.
Thus, a need exists for a heat exchanger of the type described above which can be manufactured at a relatively low cost. The invention provides such a device, which overcomes the disadvantages of other existing heat exchanger designs. These and other advantages of the present invention, as well as additional inventive features will be apparent from the description of the invention provided herein.